APOPTOSIS IN ACUTE 1YMPHOBlASTIC LEUKEMIA IN CHilDREN

Abstract

. Apoptosis or programmed cell death (PCD) is a physiologic

phenomenon that ensures the balance between cell proliferation and cell ., death. Apoptosis removes the senescent, damaged abnormal cell

interfering with the normal function of the organism. The abno alities . { l of apoptosis play an important role in the proliferative neoplasic disease, . : degenerative disorders and autoimmune disease (Schuler and Szendes,

1997).

The leukemias are the most • common form of cancers. They account for about one third of new cases of cancer diagnosed each year. The acute lymphoblastic leukemia represent the quintessential example of • I_ , malignancy caused by failed programmed cell death (Apoptosis), as•

apposed to altered cell cycle regulation. In all self-renewing tissues, new cell production is normally offset by commensurate amount of cell destruction through programmed cell death (Tsangris eta/., 1996). ., . ' .

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Imbalances in the activities of opposing genes that either promote or block physiological cell death can therefore slow or halt the rate of cell turnover, creating a selective survival advandage for a particulat cion that permit expansion, often at the expense of its normal neighbors (Thompson, 1995).

i The cell surface Fas receptors (CD95) is a cystein rich

transmembrane glycoprotein, and belongs to the nerve growtp• factor

(NGF), tumour necrosis factor (TNF) receptor family (Oehm et • al.,

1992).